GPS woes

[PRL JAM]

Any advice on pinpointing a cache location when your GPS doesn't want to cooperate?

I've been after a few caches where it will take me 50 yards in one direction, then 40 back the other way and then sometimes in random directions all around. I'm using an HTC One M9 with the free Geocaching app.

So frustrating because it just happens sometimes and I never know when it is going to happen until I get way out in the woods.

[+TriciaG]

Do you stop and let the GPS settle down a bit? I've found that if I charge ahead and go to where it says fairly soon after firing up my app (not the free Geocaching one, but the principle still applies), it'll lead me on a wild goose chase. But if I stand still for 30 seconds, then move forward the 50 yards, then wait another 30 seconds for it to sense where I now am, it works better.

 

Keep in mind that tree cover and such will disrupt the GPS signal, so sometimes getting within 5-10 yards is about as good as you'll get. From there, put away the app and use your eyes and geosenses (which will get better with experience) in the search. Very, very rarely will the GPS zero out right at the cache.

[+on4bam]

You might try to stop when getting close to the cache and wait a moment for the GPS to settle down an show a stable location. Running from left to right won't do you any good. Once you find the cache you may want to stay put for a moment and you should then be standing withing 5m (15ft) or less when looking at your app.

[+niraD]

A lot depends on why your reported location keeps varying.

 

Some variation is expected, even under ideal conditions. A consumer GPSr will be accurate to about 3m (10ft), so you can have your device sitting right on top of the geocache, with a clear view of the satellites, and over time your reported location will vary by 10ft, and perhaps a little more sometimes.

 

In areas with poor reception (e.g., heavy tree cover, steep canyons, "urban canyons" in cities), your accuracy goes down and your reported location can vary even more.

 

I've found caches where the owner apologized for the GPS reception; the owners' Estimated Positional Error (EPE) was 50-100ft, so the owner provided good hints to compensate.

 

I've also found caches where I could get good reception a moderate distance away, and then pace off the distance to the cache from there. I've also used a form of triangulation, where I got good reception in two locations, and then looked at the imaginary lines from each location towards the cache. Where the two lines intersected was my ground zero.

 

With my phone, I've occasionally had the GPS services disabled. Some power-monitoring apps will do this automatically when your battery gets low enough. The next time I tried to use my phone for geocaching, it would use the other location services (e.g., cell tower triangulation, wifi networks), which are much less accurate. Once I figured out why my reported location was varying so much, I re-enabled the GPS services, and the problem went away.

[+whh0]

Just as you say "way out in the woods" Tree cover causes big headaches for GPS's, they hate it and often swing round and round in circles. As others have said, stop, wait for it to settle but if it doesn't you are probably in the general location of the cache and then is the time to put the GPS away and start looking. Round here if the GPS signal is poor then a good hint is generally given to help locate the cache.

[+Gitchee-Gummee]

Any advice on pinpointing a cache location when your GPS doesn't want to cooperate?

I've been after a few caches where it will take me 50 yards in one direction, then 40 back the other way and then sometimes in random directions all around.

 

Yup, you are being led about here and there, to and fro... all the time your eyes are glued on the device.

It is a symptom of a new(er) cacher and the forgetful old(er) cachers.

 

Well, un-glue them from the device. When you start closing in on GZ (you already know the direction and basic distance), stop looking at the device and start looking for the cache -- or more rather, its hiding spot.

 

As stated previously, the GPSr is not going to take you TO the geocache. It is only going to get you close. You cannot expect absolute pin-point accuracy for a few reasons:

1] A consumer-grade device cannot provide you with absolute accuracy;

2] It is taking you to the COORDINATES, not the cache. The cache may (or may not) be dead-on placed -- wide and varying reason for this;

3] As you close in on the coordinates, the readings become "fuzzy" to the device. It is going to lead you here, there, back again, then this way and that way. When you notice this behavior (better yet, before it happens) put it away and look for the placement.

If you keep looking at the device you are wasting your eyesight... you should be looking for the cache.

 

Again... because it is so important... the GPSr will only take you to the AREA of the coordinates. The rest is up to you.

You'll get better as you gain experience.

[Andronicus]

Your Android based phone should work well. However, 2 things I would think could be your problem is

1) Reception. Are you under tree cover, downtown? Anything that will reduce your visibility of the sky, or cause multipath bouncing will mess us your phone's accuracy.

2) What are your location settings? On my phone running Android 4.0 (Lollipop) Settings>>Personal>>Location>>Mode>> For GPS only (Best for geocaching), select Device only. High accuracy is good to, and may help you downtown. But whatever you do, don't use Battery saving. That is absolutly no good for geocaching!

[+kunarion]

Any advice on pinpointing a cache location when your GPS doesn't want to cooperate?

Log a DNF, go find a different cache. Contact the Cache Owner for a hint.

 

As mentioned, hold the GPSr still (even place it on the ground and wait), and it may settle down. If you decide to wander, see if you tend to be led to a particular spot.

 

If there's a place with no tree cover nearby, go there and walk in a straight line perpendicular to the cache location. See where the bearing indication points, and note the distance. 120 feet is "40 paces". Walk toward the tree or whatever object the GPSr was pointing to, and pace it out.

 

Look at the satellite map, read the description and hint, and read the logs.

Edited July 7, 2015 by kunarion

[+on4bam]

Log a DNF, go find a different cache. Contact the Cache Owner for a hint.

 

As mentioned, hold the GPSr still (even place it on the ground and wait), and it may settle down. If you decide to wander, see if you tend to be led to a particular spot.

 

If there's a place with no tree cover nearby, go there and walk in a straight line perpendicular to the cache location. See where the bearing indication points, and note the distance. 120 feet is "40 paces". Walk toward the tree or whatever object the GPSr was pointing to, and pace it out.

 

Look at the satellite map, read the description and hint, and read the logs.

 

In short: Learn how your GPS works/reacts and get some experience looking for different sorts of caches. You'll get the hang of it.